Tinuvin 326 (UV-326, Bumetrizole): Properties, Uses and SVHC Status

Tinuvin 326 (UV-326, bumetrizole; CAS 3896-11-5) is a chlorinated hydroxyphenyl benzotriazole UV absorber used at 0.1 to 0.5 wt% in polyolefins, unsaturated polyester and acrylics to stop sunlight from breaking the polymer down. Since 23 January 2024 it is also a Substance of Very High Concern, which changes what a converter has to declare without changing what the additive may still be used for.

UV-326 has been on the REACH Candidate List as a vPvB substance under Article 57(e) since 23 January 2024. It is not on the REACH Authorisation List (Annex XIV); it sits only in ECHA's draft recommendation of 2 February 2026. It remains listed in Regulation (EU) No 10/2011 as FCM 470 and in 21 CFR 178.2010 for US food-contact use. UV-326 is one of 67 UV stabilizer pages in our directory of plastic additives, each carrying the same identity, dosage and regulatory fields.

This page sets out UV-326's identity and absorption mechanism, its dosage across polypropylene, polyethylene, EVA, unsaturated polyester, acrylics and PVB, its four plastics application areas, its dated regulatory matrix across REACH, EU food contact and the FDA, a substitution shortlist against six other UV absorbers, and the producers that sell it as Tinuvin 326, SONGSORB 3260, Eversorb 73, Everstab 326, BLS 1326, Lowilite 26 and Milestab 326.

Table T1: Identity and status summary for Tinuvin 326 (UV-326, bumetrizole).

What Is Tinuvin 326 (UV-326)?#

Tinuvin 326 is BASF's trade name for bumetrizole, a 2-(2-hydroxyphenyl)benzotriazole UV absorber that carries a tert-butyl group, a methyl group and, unlike most of its class, a chlorine atom on the benzotriazole ring. The molecule also carries an intramolecular O-H...N hydrogen bond between the phenolic hydroxyl and the triazole nitrogen, and that bond is the structural feature the mechanism section below depends on. Bumetrizole is another name for benzotriazole in its non-proprietary, regulator-facing form: it is the name used on REACH dossiers and on cosmetic ingredient lists, while the hydroxyphenyl benzotriazole class it belongs to is the largest chemical family of plastics UV absorbers.

Every attribute on this page, from dosage to the SVHC listing, applies to the single CAS number 3896-11-5, regardless of which trade name or generic code a supplier or a regulator uses. Readers who arrive from the UV stabilizer family hub can compare UV-326 against the other working half of the light-stabilizer system, the UV stabilizers for plastics hub, which explains how UV absorbers and hindered amine light stabilizers divide the protection job between them.

What does UV-326 stand for, and what is bumetrizole?#

UV-326 is the generic industry code for the same substance that BASF sells as Tinuvin 326, and bumetrizole is its non-proprietary chemical name, used by regulators and in cosmetic ingredient lists. Generic "UV-xxx" codes such as UV-326, UV-328 and UV-329 are the dominant shorthand in Asian trade catalogues and in search queries for this substance, running alongside brand names such as UV Absorber 326 and Light Absorber 326. Bumetrizole is the form that appears in REACH dossiers, in the EU's Drinking Water Directive positive list and, outside the plastics scope of this page, in cosmetic ingredient lists. Our source library records the name itself but not which body first assigned it, so this page does not attribute its origin to a specific standards body.

Is Tinuvin 326 the same as UV-326?#

Yes: Tinuvin 326, UV-326, UV Absorber 326, Light Absorber 326 and bumetrizole are all the same substance, CAS 3896-11-5, and every regulatory entry on this page refers to that CAS number. A supplier datasheet, a REACH dossier and a cosmetic ingredient list can use any of these five names for the identical molecule, so the CAS number is the only reliable cross-check when comparing a technical data sheet against a regulatory database. Readers checking whether a different brand's grade shares this chemistry can cross-reference it on the plastic additive trade name lookup, which maps trade names to CAS numbers and suppliers.

Which trade names sell the same chemistry as Tinuvin 326?#

Six trade names cover CAS 3896-11-5: Tinuvin 326 and Tinuvin 326 FL from BASF, SONGSORB 3260 from Songwon, Eversorb 73 and Everstab 326 from Everlight, BLS 1326 from Mayzo, plus Lowilite 26 and Milestab 326. Our source library does not record which company owns the Lowilite 26 and Milestab 326 grades, so this page names the grade without attributing it to a company. Table T9, later on this page, lists each producer beside its trade name and physical form.

How Does Tinuvin 326 Protect Plastics from UV Light?#

Tinuvin 326 absorbs ultraviolet light between about 300 and 400 nm and converts that energy into heat by excited-state intramolecular proton transfer across its internal O-H...N hydrogen bond, so the polymer never receives the photon. The process is described in the photophysics literature as excited-state intramolecular proton transfer, or ESIPT, and it is the mechanism common to the whole hydroxyphenyl benzotriazole class (J. Crawford, Prog. Polym. Sci. 24, 1999, "Vibrational spectra of oligomers", 7 to 43). Protection follows the Beer-Lambert relationship: how much UV light a given loading absorbs depends on the product of concentration and part thickness, which is why the same weight percentage protects a thick profile more completely than a thin film.

Why does polypropylene need a UV absorber at all if it barely absorbs sunlight itself? Sunlight at the earth's surface starts at roughly 280 to 290 nm, and aliphatic polyolefins on their own absorb only below about 250 nm, so photo-oxidation does not start from the polymer backbone. It starts from impurities already present in the resin, hydroperoxides, carbonyl groups and residual polymerisation-catalyst traces, which absorb in the solar range and initiate the radical chain that UV-326 and its partner stabilizers are formulated to interrupt.

ESIPT runs in three steps.

1. The molecule absorbs an incoming UV photon and moves to an excited electronic state.
2. A proton transfers across the internal O-H...N hydrogen bond while the molecule is still in that excited state.
3. The molecule returns to the ground state without emitting a photon, releasing the absorbed energy as heat instead.

The chemistry of this cycle sits inside the wider class of UV absorbers, which is compared by absorption range and volatility across every chemical type used in plastics.

Why does Tinuvin 326 need a HALS partner?#

A UV absorber cannot protect the outermost surface layer of a part, because absorption needs path length, which is why Tinuvin 326 is combined with a HALS such as Chimassorb 944 rather than used alone in outdoor articles. UV absorbers follow the Beer-Lambert relationship and are thickness-dependent, while hindered amine light stabilizers do not absorb UV at all and work independently of thickness. BASF's own HALS datasheets recommend adding a Tinuvin 326 or 328 type absorber, or UV-531, specifically in unpigmented or lightly pigmented articles, where the pigment itself provides no UV screening. In agricultural and packaging film, hindered amine light stabilizers (HALS) supply the complementary, regenerating half of the protection system, and Chimassorb 944 is the oligomeric HALS most often paired with UV-326 in film.

What Are the Physical and Chemical Properties of Tinuvin 326?#

Tinuvin 326 is a light-yellow powder that melts at 138 to 141 °C (280 to 286 °F), has a density of 1.32 g/ml at 20 °C and a vapour pressure of 7.5 x 10-7 Pa, which is why it survives polyolefin extrusion without measurable loss.

Table T2: Physical and chemical properties of Tinuvin 326 (UV-326).

Two melting ranges appear across the sources and both are correct for their own purpose. The supplier range of 138 to 141 °C comes from Mayzo and Songwon technical data sheets, while 21 CFR 178.2010 identifies the substance by a specification of 137 to 141 °C, one degree wider, because the FDA entry lists the substance by chemical name and melting point rather than by CAS number. A US food-contact compliance declaration should quote the 137-141 °C specification rather than the supplier range, since that is the identifier the regulation itself uses. No solubility figure, refractive index or boiling point for UV-326 is recorded in our source library, so none is stated here.

Which wavelengths does Tinuvin 326 absorb?#

Tinuvin 326 absorbs with maxima at 312 and 353 nm and an extinction coefficient of 15,600 l/mol cm, and a film loaded with it transmits less than 1% of the light up to 370 nm. For contrast, UV-P peaks at 301 and 341 nm and UV-329 at 301 and 343 nm, so the chlorine substituent on UV-326 shifts its absorption roughly 10 nm further toward the visible edge of the spectrum than the non-chlorinated members of the class. That shift is simple arithmetic on the measured maxima; it is not evidence of a performance advantage, and this page does not claim that a red-shifted absorber protects better than a non-shifted one.

Which Polymers Use Tinuvin 326, and at What Dosage?#

Tinuvin 326 is dosed at 0.1 to 0.5 wt% in polypropylene, 0.1 to 0.4 wt% in polyethylene and EVA and 0.2 to 0.5 wt% in unsaturated polyester, always as part of a system with a hindered amine light stabilizer.

Table T4: Tinuvin 326 dosage by polymer.

Does the same percentage apply whatever the part thickness? No: because UV absorbers follow the Beer-Lambert relationship, the effective protection a given weight percentage delivers rises with part thickness, which is why the performance section below treats thickness and dosage together rather than dosage alone. Ranges for every additive family, not only UV absorbers, are collected on additive dosage levels in plastics, which explains how phr and wt% figures convert between polymer systems.

Tinuvin 326 in polypropylene#

Polypropylene takes 0.1 to 0.5 wt% Tinuvin 326 according to the BASF datasheet, and it needs that protection more than any other commodity polyolefin because its tertiary carbon-hydrogen bonds are the easiest to abstract. Unpigmented and lightly pigmented PP parts, where no filler or colourant provides incidental UV screening, are the cases where the full dosage range and a HALS partner both matter most. The complete PP stabilizer package, including HALS selection, is set out on UV stabilizers for polypropylene.

Tinuvin 326 in polyethylene and EVA film#

Polyethylene and EVA films carry 0.1 to 0.4 wt% Tinuvin 326 in the BASF range and up to 0.5 wt% in the Mayzo equivalent grade, on top of 0.1 to 1.0 wt% of an oligomeric HALS such as Chimassorb 944. Agricultural film formulations sit toward the upper end of both ranges, since greenhouse covers face a longer UV dose than most packaging film. Film and pipe systems for polyethylene are compared in full on UV stabilizers for polyethylene.

Tinuvin 326 in unsaturated polyester, acrylics and PVB#

Unsaturated polyester takes the highest plastics loading of Tinuvin 326, 0.2 to 0.5 wt% in the Mayzo grade, while acrylics and PVB interlayers appear in the supplier application lists without a published dosage range. Where our source library carries no numeric range for a listed application, this page states that plainly rather than estimating one.

What Is Tinuvin 326 Used For? 4 Application Areas in Plastics#

Tinuvin 326 is used in 4 plastics application areas: polyolefin film and packaging, agricultural film, unsaturated polyester and acrylic parts, and PVB interlayers.

• Polyolefin film and rigid packaging, including food-contact applications
• Agricultural and greenhouse film, combined with a HALS
• Unsaturated polyester laminates and acrylic composite parts
• PVB (polyvinyl butyral) interlayers

Coatings, adhesives and sealants also appear in supplier application lists for bumetrizole, but those uses sit outside the plastics scope of this reference and are named once, below the contextual border.

Polyolefin film and packaging#

Polyolefin film and rigid packaging are the main plastics outlet for Tinuvin 326, and it is one of the few benzotriazole absorbers cleared on both sides of the Atlantic for food-contact polyolefins. Its EU clearance runs through FCM 470 with group restriction 12, and its US clearance runs through 21 CFR 178.2010 for olefin polymers complying with 21 CFR 177.1520(c). The full additive package for film and rigid packaging, including slip, antiblock and antifog agents alongside the UV package, is covered on additives for packaging film.

Agricultural film#

Agricultural film uses Tinuvin 326 as the absorber half of a HALS plus UVA package, because a greenhouse cover has to survive both the UV dose and the agrochemical residues that attack the stabilizer itself. Raising the sulfur residue in a film from about 1,000 to 2,000 ppm, a level associated with certain sulfur-based agrochemicals, cut greenhouse film life by 20 to 25% according to the AMI Agricultural Films conference (2010), which illustrates why the UVA and HALS loading in greenhouse film is set higher than in general packaging film. Radiation dose in kLy and pesticide resistance for this application are covered in full on UV stabilizers for greenhouse and agricultural film, and the complete film recipe, additive by additive, is set out on additives for agricultural film.

Unsaturated polyester and composite parts#

Unsaturated polyester laminates and gel-coated composite parts take 0.2 to 0.5 wt% Tinuvin 326 to slow the yellowing and surface chalking that follow outdoor exposure. No yellowing-index values specific to UV-326 in unsaturated polyester are recorded in our source library, so this page describes the failure mode without quantifying it.

How Does Tinuvin 326 Perform, and How Is It Tested?#

Tinuvin 326 loses 1% of its weight at 180 °C in thermogravimetric analysis, which places it in the mid range of the benzotriazole absorbers, above UV-P at 153 °C and far below Tinuvin 234 at 264 °C.

Table T5: Performance indicators and test standards for Tinuvin 326.

How is that protection actually verified? Cycle definitions for the accelerated weathering tests used across the class, ISO 4892-2 and ASTM G155 for xenon-arc exposure and ASTM G154 or ASTM D4329 for fluorescent UV exposure, cover the method only; outdoor exposure follows ASTM D1435 or ISO 877; colour change is reported as the yellowness index under ASTM E313. No UV-326-specific weathering result, whether hours to failure, retained tensile strength or delta yellowness index, is recorded in our source library, so this page names the test methods without publishing a value and states no service life in years for UV-326.

How volatile is Tinuvin 326 at processing temperature?#

At 180 °C Tinuvin 326 has lost 1% of its mass, which is comfortable for polyolefin extrusion but not for polycarbonate or PET, where melt temperatures of 270 to 300 °C call for Tinuvin 234, Tinuvin 1577 or Cyasorb UV-3638 instead. This TGA ranking is the practical selection tool for matching an absorber to a process: an absorber that loses mass below the melt temperature of its target polymer is lost during processing rather than protecting the finished part. The full volatility and absorption comparison across the class sits on the benzotriazole UV absorbers hub.

How Does Tinuvin 326 Interact with Other Additives?#

Tinuvin 326 is formulated as one half of a two-mechanism system: it removes the photons, and a hindered amine light stabilizer removes the radicals that the surviving photons create.

• Hindered amine light stabilizers (HALS): a complementary, non-competing mechanism. HALS regenerate through the Denisov radical-scavenging cycle rather than being consumed in a single event (E. T. Denisov, Polym. Degrad. Stab. 34, 1991, "Mechanism of the retarding action", 325 to 332, reviewed by Pieter Gijsman, Polym. Degrad. Stab. 145, 2017, "Photostabilization of polymers by hindered amine stabilizers", 2 to 10).
• Phenolic antioxidants and phosphites: base stabilization during melt processing, protecting the polymer from thermo-oxidative degradation before the part ever sees outdoor light.
• Pigments: some pigments provide incidental UV screening and reduce the UV absorber's workload, while others can photo-sensitise degradation instead, so the pigment system is never assumed to be neutral.

Our source library records no acid, pigment or metal-ion antagonism specific to UV-326 itself. Iron and cobalt complexation is a documented issue for UV-P, a related but different benzotriazole, and this page does not transfer that fact to UV-326.

What Is the Regulatory Status of Tinuvin 326?#

UV-326 is registered under REACH, has been on the REACH Candidate List as a vPvB substance since 23 January 2024, is not on the Authorisation List, and is still authorised for food-contact plastics in both the EU and the United States (status 22 September 2026).

Table T6: Regulatory matrix for Tinuvin 326 (UV-326), as of 22 September 2026.

The unique asset of this page is a single table that places UV-326 beside the seven other members of its chemical class and their Candidate List, Annex XIV and Stockholm Convention status.

Table T7: The benzotriazole UV absorber cascade. Annex XIV entries 51-54 carry a latest application date of 27 May 2022 and a sunset date of 27 November 2023 with no exempted uses (Commission Regulation (EU) 2020/171, 6 February 2020).

How registration, evaluation, authorisation and restriction fit together is explained on REACH and plastic additives, and all eight phenolic benzotriazoles are tracked with their dates on benzotriazole UV absorbers: SVHC, Annex XIV and POPs status.

Is UV-326 an SVHC?#

Yes: UV-326 has been on the REACH Candidate List since 23 January 2024, identified as very persistent and very bioaccumulative (vPvB) under Article 57(e) of Regulation (EC) No 1907/2006. The listing is not a ban: it creates information duties, and UV-326 may still be manufactured, imported and used in the EU. ECHA concluded its own PBT assessment on 1 February 2024, the same review that produced the Candidate List entry. UV-326 is a vPvB substance only; it is not classified as PBT, unlike its siblings UV-320 and UV-328. Every plastic additive on the SVHC Candidate List is listed with its inclusion date and Article 57 ground, and what PBT and vPvB substances means in regulatory practice is defined separately.

What do Article 33, SCIP and Article 7(2) require above 0.1%?#

Because Tinuvin 326 is dosed at 0.1 to 0.5 wt%, a stabilized article frequently sits above the 0.1% w/w threshold that triggers all four Candidate List duties. Four obligations follow once a UV-326-stabilized article crosses that threshold.

1. Article 33 communication: suppliers must tell recipients when an article contains the substance above 0.1% w/w, and must answer a consumer request within 45 days.
2. SCIP notification: articles above the threshold are notified to the SCIP database under the Waste Framework Directive, Article 9(1)(i), in force since 5 January 2021.
3. Article 7(2) notification to ECHA: required above 0.1% w/w and 1 tonne per year per actor, within 6 months of the substance's Candidate List inclusion.
4. Safety data sheet on request: required under Article 31(3) for mixtures containing at least 0.1% of the substance.

Is UV-326 on the REACH Authorisation List (Annex XIV)?#

No: UV-326 is not on REACH Annex XIV, and no authorisation is required to use it today; it sits in ECHA's draft recommendation published on 2 February 2026, whose consultation ran to 2 May 2026 and had produced no final recommendation by 22 September 2026. That draft recommendation also names UV-329, triphenyl phosphate and photoinitiator 379 alongside UV-326. Four other benzotriazoles, UV-320, UV-328, UV-327 and UV-350, are already on Annex XIV as entries 51 to 54, with a latest application date of 27 May 2022 and a sunset date of 27 November 2023 and no exempted uses, which is what an eventual UV-326 inclusion would be expected to resemble in form, though this page states no date for that outcome because none has been proposed in a published act. The four benzotriazoles already on the REACH Annex XIV Authorisation List show what an inclusion looks like in practice.

Is Tinuvin 326 allowed in food-contact plastics in the EU?#

Yes: UV-326 is FCM substance 470 in Annex I of Regulation (EU) No 10/2011 and may be used as an additive in plastic food-contact materials, subject to group restriction 12, a total specific migration limit of 30 mg/kg shared with UV-P and UV-327. The pairing with UV-327 illustrates a paradox competitors miss: UV-327 remains in the same group restriction as UV-326 even though its own REACH sunset date passed on 27 November 2023, so an Annex I food-contact entry is not on its own proof that a substance may still be freely used in the EU under REACH. Group restrictions, the fat reduction factor and the overall migration limit are explained on EU 10/2011.

Is Tinuvin 326 cleared by the FDA?#

UV-326 is listed in 21 CFR 178.2010, the FDA's list of antioxidants and stabilizers for polymers, at up to 0.5 wt% in olefin polymers that comply with 21 CFR 177.1520(c). The entry identifies the substance by its melting-point specification of 137 to 141 °C rather than by CAS number, so a declaration of compliance for a US food-contact application should quote that specification, not the CAS number, as the regulatory identifier. Food types and conditions of use are decoded in full on 21 CFR 178.2010.

Is Tinuvin 326 allowed in drinking-water contact?#

Yes: UV-326 holds entry 0406 on the European positive list of starting substances for materials in contact with drinking water under Directive (EU) 2020/2184. UV-327 holds the neighbouring entry 0405, and UV-P holds entry 0381 on the same list. The European positive list and the comparable US and German schemes are compared on plastic additives in drinking-water contact.

Is Tinuvin 326 Safe? Health, Safety and Environmental Profile#

UV-326 has no EU harmonised hazard classification under Regulation (EC) No 1272/2008, and 79% of the companies that notified it to ECHA classify it as H413, may cause long-lasting harmful effects to aquatic life. Its regulatory problem is not acute toxicity but persistence: ECHA concluded its PBT assessment on 1 February 2024 and identified the substance as very persistent and very bioaccumulative.

• Classification: no EU harmonised entry under CLP; 79% notifier-classified H413 (aquatic chronic hazard)
• Persistence and bioaccumulation: identified vPvB under Article 57(e), PBT assessment concluded 1 February 2024
• Regulatory consequence: Candidate List declaration duties apply above 0.1% w/w in an article; the substance is not restricted and not banned

This page does not describe UV-326 as "safe", "non-toxic" or "eco-friendly" without qualification, because the substance carries an active regulatory concern for environmental persistence. No LD50, no NOAEL and no bioaccumulation factor for UV-326 is recorded in our source library. The log Kow of 7.93 and the log BAF range of 2.6 to 3.4 sometimes cited for benzotriazole UV absorbers belong to UV-328, a different substance, and are not transferred to UV-326 on this page. The difference between a harmonised and a notified classification is explained on CLP classification of plastic additives.

What Can Replace Tinuvin 326?#

Six substitutes are recorded for UV-326: Tinuvin 234, Tinuvin 1577, Cyasorb UV-1164, Cyasorb UV-3638, Tinuvin 312 and UV-531, and the choice turns on two questions, whether the replacement is itself on a regulatory track and whether it is listed for the food contact the part needs.

Table T8: Substitution matrix, status as of 22 September 2026. Tinuvin 312 (oxanilide, CAS 23949-66-8, FCM 633, SML 30 mg/kg) and Cyasorb UV-3638 (benzoxazinone, FCM 796, SML 0.05 mg/kg including hydrolysis products) complete our source library's substitution list.

Full class data for every chemical type covered here sit on the hub for types of UV absorbers.

UV-326 vs UV-328#

UV-328 is not an alternative to UV-326 but its predecessor: it is the first non-halogenated plastic additive listed as a persistent organic pollutant, banned in the EU under Regulation (EU) 2019/1021 since 4 August 2025, while UV-326 is only on the Candidate List. UV-328 was added to the Candidate List on 17 December 2014 as both PBT and vPvB, placed on Annex XIV as entry 51 with a sunset date of 27 November 2023, then listed under the Stockholm Convention by decision SC-11/11 at COP-11 in May 2023. The EU implemented that listing through Delegated Regulation (EU) 2025/843, in force since 4 August 2025, with unintentional trace contaminant limits of 100 mg/kg from 4 August 2025, falling to 10 mg/kg from 4 August 2027 and 1 mg/kg from 4 August 2029. Its full profile is on UV-328 (Tinuvin 328), and how a Stockholm listing becomes an EU limit is set out on POPs in plastics.

UV-326 vs UV-329 and UV-327#

Switching from UV-326 to UV-329 solves nothing in the EU: both were added to the Candidate List on the same day, 23 January 2024, and both appear in the same draft Annex XIV recommendation of 2 February 2026. UV-327 is further along the same regulatory path: its Annex XIV sunset date passed on 27 November 2023, yet it remains listed as FCM 469 in Annex I of Regulation (EU) No 10/2011, the same paradox that applies to UV-326's own food-contact entry. UV-329 (octrizole) was listed on the same day and for the same reason as UV-326. Tinuvin 327 shows what happens after a sunset date passes: the FCM entry survives, the EU use does not.

UV-326 vs Tinuvin 234#

Tinuvin 234 is the higher-molecular-weight benzotriazole that replaces UV-326 where the melt is hot: its 1% weight loss sits at 264 °C against 180 °C, and it is not on the Candidate List as of 22 September 2026. The substitution is not risk-free: ECHA has had Tinuvin 234 under PBT assessment since the expert-group written procedure of 5 September 2025, so its regulatory status could still change. Tinuvin 234 is the high-temperature benzotriazole, and it is under PBT assessment rather than on the Candidate List.

UV-326 vs Tinuvin 1577 and Cyasorb UV-1164#

The two hydroxyphenyl triazines are the structural exit from the benzotriazole class: Tinuvin 1577 and Cyasorb UV-1164 are neither on the Candidate List nor under a published PBT assessment, and both hold EU food-contact entries in their own right. The trade-off is the food-contact limit itself: Tinuvin 1577 carries an SML of 0.05 mg/kg against the 30 mg/kg group limit that covers UV-326, and the FDA caps UV-1164 in polyolefins at 0.3 wt%, below the 0.5 wt% allowed for UV-326. Tinuvin 1577 leaves the benzotriazole class entirely, and Cyasorb UV-1164 is the triazine written for polyolefins rather than for polycarbonate.

UV-326 vs UV-531#

UV-531 is the non-SVHC absorber that sits closest to UV-326 in the same markets, polyolefin film and agricultural film, at 0.1 to 0.7 wt% and with the same 0.5 wt% FDA cap in olefin polymers. BASF positions its own UV-531 grade, Chimassorb 81, for applications where durability expectations are moderate, rather than describing UV-326 itself as weaker. UV-531 (Chimassorb 81, octabenzone) covers the same film markets without a Candidate List entry.

Who Manufactures Tinuvin 326? Grades and Suppliers#

UV-326 is made by four producers recorded in this directory, BASF, Songwon, Everlight Chemical and Mayzo, and sold under at least six trade names for the same CAS number, 3896-11-5.

Table T9: Producers and grades for UV-326. Grades sharing a CAS number are not interchangeable without the supplier's own specification, and physical form data beyond "light-yellow powder" is not recorded for every grade.

The global UV stabilizer market was valued at USD 2.53 billion in 2024 and is forecast to reach USD 3.72 billion by 2030, a compound annual growth rate of 6.76% for 2025 to 2030 (MarketsandMarkets, May 2025). Buyers should ask the supplier for the TDS, the SDS and a written Candidate List statement, because a 0.1% threshold in the finished article turns on the exact loading used. No price data for UV-326 is recorded in our source library, so this page states no price. Plants, portfolios and certifications by company are in the directory of UV stabilizer and HALS manufacturers.

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Where Does UV-326 Sit in the Benzotriazole UV Absorber Family?#

UV-326 is the chlorinated member of the hydroxyphenyl benzotriazoles, the largest chemical class of UV absorbers, which sits beside the benzophenones, the hydroxyphenyl triazines, the oxanilides and the cyanoacrylates inside the UV stabilizer family. Across the benzotriazole class, the older members, UV-328, UV-327, UV-320 and UV-350, are already regulated off the market or moving through Annex XIV, and the newer hydroxyphenyl triazines, Tinuvin 1577 among them, are the structural direction the industry is moving toward as those older grades sunset. About 70% of global light stabilizer production, UV absorbers and HALS combined, goes into polyolefins, which is why the polypropylene and polyethylene dosage tables above carry the page's most consulted numbers. The general logic for choosing among UV stabiliser classes, polymer first, then process, then regulation, is set out in how to select plastic additives.

Uses of bumetrizole outside plastics#

Outside plastics, bumetrizole is used in coatings, adhesives and sealants, and it appears in cosmetic ingredient lists under the same name, all of which fall outside the scope of this reference. In coatings, the UVA dosage scales directly with dry film thickness under the Beer-Lambert relationship: roughly 2.5 to 5% on solids at 10 to 20 µm, 1.25 to 2.5% at 20 to 40 µm and 0.5 to 1.25% at 40 to 80 µm, the clearest illustration on this page of how thickness and concentration trade off against each other. This site does not cover coating formulation, adhesive formulation or cosmetic ingredient safety, and none of those uses changes the plastics data given above.

Is Tinuvin 326 banned?#

No: as of 22 September 2026 Tinuvin 326 may be manufactured, imported and used in the EU and the United States, and it is neither restricted under REACH Annex XVII nor listed under the POPs Regulation. The Candidate List entry of 23 January 2024 creates declaration duties, not a prohibition. The draft Annex XIV recommendation of 2 February 2026 could change that in a future amending regulation, which is why this page carries a status date and belongs on a scheduled regulatory review.

Is UV-326 the same as UV-327?#

No: UV-327 (CAS 3864-99-1) carries two tert-butyl groups where UV-326 carries a tert-butyl and a methyl group, and unlike UV-326 it has required an authorisation in the EU since its sunset date of 27 November 2023. UV-327 was added to the Candidate List on 17 December 2015 and sits on Annex XIV as entry 52, one regulatory step further along the same path that UV-326's own draft recommendation could eventually follow.

Where do the TDS and SDS for Tinuvin 326 come from?#

Each producer issues its own technical data sheet and safety data sheet for its grade, and since the 2024 Candidate List entry an SDS must also be supplied on request for mixtures containing 0.1% or more of UV-326. This site does not host or reproduce supplier datasheets; readers should request the current TDS and SDS directly from the producer named in Table T9.

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Every figure on this page is checked against primary sources; see our methodology and fact-checking process.